Strain insulator



Patented `lune 20, 1939 UNITED STATES PATENT OFFICE Claims.

'Ihe principal object of the present invention is to provide a strain insulator which shall be comparatively simple and inexpensive to make and assemble and which shall be eiiicient and reliable in operation and use.

Other objects of the invention will appear from the following description at the end of which the invention will be claimed.

Generally stated the invention comprises metal link members provided with aligned openings, thimbles of insulating material having heads and stems, the stems being arranged through and extending outside of the openings in the link members, and the heads being arranged inside of the links, headed connectors arranged through the thimbles with their heads in contact With the heads of t'he thimbles, and an insulating casing in which the structure is arranged with a filling of insulating material and outside of which the end connectors project to provide means of attachment.

The invention also comprises the improvements to be presently described and finally claimed.

In the following description reference will be made to the accompanying drawing forming part hereof and in which,

Figure l is a vertical transverse sectional view of a strain insulator embodying features of the invention and showing portions of the lling omitted for the sake of clearness; and

Fig. 2 is a transverse sectional view taken on the line 2-2 of Fig. 1.

Referring to the drawing I and 2 indicate link elements provided with aligned openings 3. As .7 shown the link elements I and 2 are duplicates and are arranged as indicated in the drawing but the form and construction of the link elements is not essential, for example, one of the link elements may be employed without the other and it is not essential that the opening bounded by the link elements should be rectangular or of any particular shape. There are thimbles of insulating material provided with stems 4 and heads 5.

The stems 4 of these thimbles are arranged thru the openings 3 in the link elements and they extend outside of and beyond the latter. The heads 5 of the thimbles are arranged inside of the link elements and abut upon the end walls thereof. 6

indicates connectors respectively arranged through the thimbles of two adjacent links and the connectors are long enough to insure that the link elements shall be spaced apart. The connectors 6 are provided with heads l, and washers 8 are shown as interposed between the heads of the connectors and the at faces of the heads of the thimbles. As shown the connectors consist of metallic bolts but their form is not essential. It Will be observed that the heads 'l of the connectors, as well as the ends thereof, are spaced apart'. The described structure is housed in a casing of insulating material 9, the casing 9 is shown as provided with heads I0 of insulating material and the heads are shown a's strung on the end connectors 6 along with washers Il. The casing is lled with insulating material as indicated at I2 but only a part of the insulating material is shown. The portions of the end connectors which project outside of the heads I0 serve as a means for the attachment of ordinary strain cables or the like although such means are not shown on the drawing except as they are indicated by the parts I3 of eyes such as are usually provided on eye bolts, but such means are too well understood to require either description or illustration.

From the foregoing description it is evident that the described structure can be made to resist any strain to which it is likely to be subjected when interposed in ordinary strain cables; furthermore it consists of simple and easily constructed parts and it opposes the passage of electric current thru it because the insulating thimbles interrupt every possible path that the current might follow, and they do this efficiently because they are disposed in series and a structure containing any required number of them can be readily provided.

It may be said that Bakelite is a satisfactory material from which to construct the thimbles and also the heads of the casing; however, the material of the casing and of the iilling is not important so long as it is insulating because it is not subject to any material strain.

'I'he feet of the link elements are inturned and are flat faced where the openings 3 occur to provide a good bearing for the heads 5 of the insulating thimbles and permitting relative movement between the succeeding links.

It will be obvious to those skilled in the art that modifications may be made in details of construction and arrangement without departing from the spirit of the invention which is not limited as to such matters or otherwise than the prior art and the appended claims may require.

I claim:

1. A chain-like strain insulator comprising metal link elements having at each end inturned substantially flat face feet provided with aligned openings, insulating thimbles arranged thru said openings and having stems projecting outside of the link elements and having heads in contact With the substantially flat faces inside of the link elements, said heads being spaced apart inside of the link elements, and headed connectors arranged thru the thimbles of adjacent link elements and having their heads in contact With the faces of the thimbles, the heads of the connectors in each link element' being spaced apart.

2. A strain insulator substantially as set forth in claim l and provided with an insulating casing iilled With insulating material Which houses the structure.

3. A chain-like strain insulator consisting of duplicate metal link elements assembled in pairs to form links and provided at each .end withinturned over-lapping substantially flat faced feetv having aligned openings, insulating thimbles having stems extending thru the openings and outside thereof and having heads disposed inside of the links and spaced apart, and connectors arranged thru the 'thimbles and having heads engaging the same, the heads of the connectors being spaced apart in each link and the connectors being `long enough to provide for spacing the links apart.

.. saidinsulator comprising, a casing of insulating material, a plurality of spaced and aligned connectors of which the end connectors are attached `to and project from said casing, a plurality of spacedrnetal links within said casing each interposed betvveen an adjacent pair of said connectors and receiving portions of said connectors therethrough,V thimbles of insulating material interposed betvveen said connectors and said links, and detachable means each secured to one of said connectors and bearing on aportion of one of said thimbles so as to hold said thimble against said link.

GEORGE S. VAN ANTWERP." 

